FR2629018A1 - Material with variable optical properties - has surface layer of honeycomb-type cellular structure coated in thin metal film for reading by external laser beam - Google Patents

Abstract

The material consists of a semi-rigid plastics substrate which carries a honeycomb-type structure of sub-microscopic dimensions. The structure corresponds in size, shape and spacing to a particular optical frequency. The surface of the material may be read by a laser beam to give a signal equivalent to silence. The substrate is coated by a metallic film thin enough not to affect the dimensions of the honeycomb structure, and this is coated by a glaze film. USE - In mfr. of compact discs and similar information storage systems. (7pp)

Description

FRENCH REPUBLIC Publication no .: 2,629,018 (use only

  for NATIONAL INSTITUTE reproduction orders)

INDUSTRIAL PROPERTY

  D National registration number 88 04245 PARIS

(Int Cl ': B 44 F 1/04, 1/14.

A1 PATENT APPLICATION

  Filing date: March 28, 1988. Q Applicant (s): S.A. INVESTMENTS - STUDIES AND

ADVICE. - FR.

( Priority

    Inventor (s): Philippe Parmentelas.

  (Date of public availability of the

  application: BOPI "Patents" n 39 of September 29, 1989.

  (References to other national documents appearing

rented: () Holder (s):

  (Agent (s): Cabinet Meyer & Courtassol.

  New material with original surface optical properties and its applications.

  (New material with superficial optical characteristics

  skies variable depending on the light source, its nature and its position characterized in that it consists of a semi-rigid plastic support carrying a set of cells

  corresponding, by their shape, their size

  ion and their distribution, at a single frequency, the reading of these cells by a laser beam resulting in silence, this support being coated with a metallization sufficiently thin to not affect said network of cells, said metallization being coated with '' a protective varnish film

compatible with said support.

  I, oe DL N N LL D Sale of booklets to IMPRIMERIE NATIONALE, 27. rue de la Convention - 75732 PARIS CEDEX 15 The present invention relates to a new industrial product, its applications in particular in all related fields

  decoration, as well as a process for obtaining it.

  This product is related, by its structure and its properties, while presenting fundamental differences with it to the composite materials used for the realization of supports of sound and / or visual recordings, currently designated under the name of "compact discs" and intended to be "read" by means of one or more laser beams in

  sound and / or image production apparatus.

  We know that in recent years a completely new technique of recording and reproducing sounds and images has spread by means of a recording medium constituted by a polycarbonate resin disc conveying information coded by digitization, corresponding to sounds and / or images, in the form of sub-microscopic cells created by a laser beam etching process, coated with an extremely thin metallization and which, by reflecting one or more reading laser beams, make it possible to restore under practically ideal quality conditions the sounds and / or the

recorded images.

  This very complex technology for recording and reproducing sounds and images has been developed since 1971 by highly qualified companies, the first of which was PHILIPS, to which the credit for

  this revolutionary progress in the audio-visual field.

  The present invention is based on the observation of a physical phenomenon directly linked to the structure of compact discs. Indeed the presence on the surface of the disc of billions of cells with a dimension of the order of 0.1 to 1 micron gives rise to a diffraction-refraction process of an ordinary beam of light coming to strike this surface. In other words, it can be seen that any incident beam of ordinary light is reflected by the surface of a compact disc in the form of a beam decomposed in accordance with the spectrum of said ordinary light, with the creation of a colored effect, comparable by example to the rainbow created by the diffraction of light by the billions of

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  micro-droplets of water from a cloud of rain or mist, It is certain that this phenomenon, of which we can glimpse the applications in the field of ornamentation and decoration, is linked to the structure of compact discs intended the reproduction of sounds and / or images. The invention essentially consists in creating the same phenomenon by using a material having analogies with said compact discs, but -distinguishing fundamentally in that this material does not contain any coded information, that is to say neither does not allow reproduction of any sound or image. In addition, the material according to the invention may be in the form of non-circular flat surfaces, and even of non-circular surfaces.

  flat, depending on the applications envisaged.

  The new product according to the invention is essentially characterized in that it consists of a plastic support, preferably but not necessarily of resin

  polycarbonate, carrying a set of sub- cells

  microscopic corresponding, at the recording as at the reading, to a single frequency; such a signal would result in silence in a reading device in the event that said product lends itself to a laser reading process, which is possible, in the form of a disc, but not at all obligatory, the surface of this plastic support being coated with a metallization sufficiently thin to allow the network of aforementioned cells to remain, said metallization being itself preferably protected by a thin film of a

  varnish compatible with the plastic support.

  Such a product according to the invention, although devoid of any utility in the audio-visual field, constitutes a completely new raw material, having the remarkable property of appearing under any known lighting having all the colors of the light spectrum , variable according to the angle under which it is observed, and according to the nature

of said lighting.

  Such a new material can therefore lend itself to all the applications in which this optical phenomenon brings

  enrichment with decorative or ornamental properties

  tation of objects, whatever the technical field considered:

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  Thus, it can be used in the decoration of all articles involved in daily life: furniture, lighting, clothing (buttons, jewelry), accessories of everyday life (frames, lights, handles, kitchen utensils, electric switches, boxes all appliances, wall coverings); it can be usefully used in signs, advertisements, traffic signs: it can be substituted for light metals, for example in accessories and equipment in cars and aeronautics, and more generally still it is substituted for surfaces currently made of simple plastics, o the color of

  the matter will become multiple and changing.

  The manufacture of the new material according to the invention is a variant of the known method of manufacturing compact discs, in that, instead of etching by means of a laser beam a "glassmaster" (or photosensitive layer carried on a glass plate ) carrying cells corresponding by their shape and their spacing to the digitalization of the magnetic sound recording of a musical work and / or a visual film, one engraves on this "glassmaster" only a neutral signal with single frequency or "etching of silence", without any

audio-visual utility.

  The subsequent exploitation of the "glassmaster" to the creation of nickel matrices by electroplating is done in a usual known manner, with the difference that no control is no longer necessary since no audio-visual work is recorded, l obtaining the final material is much faster, therefore less costly than that of a compact disc

musical or video.

  Furthermore, several variants of this method are provided by the invention, and lead to embodiments

  different from the same new material.

  According to a first variant, instead of a circular support, obviously compulsory for a compact disc, the product according to the invention can be in the form of flat plates of any other shape, in particular rectangular, more convenient to machine or to work by the following. In this case, the cells, instead of being engraved in a spiral pattern like on a disc, are engraved in lines

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  rectilinear, by means of an appropriate piloting of the laser according to rectangular or oblique coordinates, in a manner known in

  oneself, for example for the production of holograms.

  According to a second variant, the mold intended for the production of the product according to the invention can be non-planar. In this case the cells are created on a lighter and deformable matrix, and the product is obtained by injection of the support material inside the mold or outside (with a second mold face). It then becomes possible to directly produce three-dimensional objects having the optical properties of the material according to the intention, such as for example pen bodies, lamp bases, flasks and decanters,

  vases, cutlery handles or toilet utensils ...

  Of course, the product and the method according to the invention may be associated with other known techniques and their results. Thus, the "mother" version of the galvanoplastic copy of the "glassmaster" could be the subject of photochemical attacks of nickel to create there inscriptions and / or additional decorations, which will come on the matrix in the form of "matrixed engraving", from which the metallization of the final product will retain the reproduction or imprint, which will combine with its characteristic optical appearance. Of course, although the new product according to the invention is preferably made of polycarbonate resin metallized with aluminum, in a manner analogous to compact discs, the requirements with which this product must comply being less severe than those of compact discs, it is possible to use for its production other materials which are more suitable for certain applications, in particular resins which are less rigid and less brittle than polycarbonates. Conversely, other metals may be better suited than aluminum for the metallization of these resins. Many variants of the invention can therefore be designed, depending on the uses envisaged for this new product. We can in particular evoke scientific applications of the optical phenomena which characterize this product, and which, while deviating from the applications purely

  artistic, fall within the scope of the present invention.

Claims (10)

  1. New material with variable surface optical characteristics depending on the light source, its nature and its position, characterized in that it consists of a semi-rigid plastic support carrying a set of corresponding sub-microscopic cells, by their shape, their size and their distribution, at a single frequency, the reading of these cells by a laser beam resulting in a silence, this support being coated with a metallization sufficiently thin to not affect said network of cells, said metallization being coated with a   protective varnish film compatible with said support.   2. Material according to claim 1, characterized in that it is produced in the form of a compact disc carrying a   signal known as "etching of silence".   3. Material according to claim 1, characterized in that it is in the form of a non-circular flat plate,   the cells being etched in rectilinear patterns.   4. Material according to claim 1, characterized in that it is in three-dimensional form, the cells   being created on the outer face of said shape.   5. Material according to any one of claims 1 to   4, characterized in that the metallization is made of aluminum.   7. Method for obtaining a material according to one   any one of claims 1 to 6, characterized in that it   consists in etching, by means of a laser beam on a photosensitive layer carried by a glass plate, submicroscopic cells whose shape and spacing correspond. to digitizing the magnetic sound recording of a neutral signal at a single frequency, to copy in known manner with nickel said so-called "original" engraving by electroplating successively a first time, as a single molding copy, then a second time as a "mother", then a third time as a "matrix" used to press a high number of products according to the invention, said galvanoplastic copies requiring no control, and finally, to press by injection said products according to ' the invention, to deposit over a metallization and finally to deposit   over a protective cover.   8. Method according to claim 7, characterized in that it is carried out in a known manner, on successive circular supports. 9. Method according to claim 7, characterized in that the support is rectangular, the laser engraving beam being piloted in an appropriate manner to engrave cells the along linear patterns.   10. Method according to claim 7, characterized in that the material of the "matrix" is light and deformable so as to allow injection molding of materials according to   the invention for obtaining three-dimensional products.   11. Application of the materials according to claims 1 to   6 to the production of products having the property of appearing under any lighting, as having   all the colors of the light spectrum of this lighting.   12. Application of the materials according to claims 1 to   6, to the production of products which can be used for the decoration and enrichment of articles involved in daily life: furniture, lighting, clothing (buttons, jewelry), accessories of everyday life (frames, lights, kitchen utensils, switches, enclosures, wall coverings); signs, advertisements, signage; substitutes for aluminum and plastics, especially in accessories and   automotive and aeronautical equipment.